I've wired a simple LED to respond to a music audio signal as per the schematic, however my LED stays lit as soon as I connect to something, music playing or not. Anything I'm doing wrong?
LED: 2.8V ...

I am just reading the latest news on the air plane crash that happened couple days ago and it dawned on me that one too many times have I read a story where after black box is obtained, it provided no ...

I'm working on a permeability measurement project and my setup includes a primary as well as a secondary side of a coil. I need to measure the flux through the coil, hence on my secondary side I have ...

I am trying to work out what resistor to use in a circuit.
The circuit is a series circuit. The power to the circuit is 5.5V, with a switch, which connects to a GPIO pin on the RasberryPi. I believe ...

I am trying to build a simple LED flasher circuit using 555 timer IC. Tried building it on breadboard and simulators several times but that is not working. As I am a beginner I think I am making some ...

if current flows through phase and fed to the desired circuit and electrons after travelling through circuit and comes out through neutral and then to ground. then what make circuit work if electrons ...

I am working on project to detect overspeeding through sensor.
but i am not getting any information regarding sensor.
All i want to do, sensor inside vehicle with arduino and gsm which will send out ...

I am trying to bias the filament of an electron gun to -575 V, but I need to switch it on and off using a TTL signal. I have an idea for how to do it, but I would like to know if it will work before I ...

What circuit can generate the waveform shown below upon receiving a falling edge trigger?
The closest I've gotten is that it looks like an RLC that got charged then the loop got closed. I'm guessing ...

Can an electric circuit do recursion?
By recursion I mean any kind of recursion, tail, binary, nested, etc: http://www.sparknotes.com/cs/recursion/whatisrecursion/section2.rhtml
By electric circuit ...

I want to calculate the gain and the phase shift of the phase shifting circuit below. My approach is to derive equations to different meshes using Kirchoff's law, and then calculate the ratio between ...

Trying to find the Thevenin equivalent voltage for the circuit on the picture below.
This voltage is supposed to be found at the round dots to the very right in the circuit.
According to the answer ...

I have a red laser pen module:
http://space-linker.com/Uploadfiles/UploadFile/2010178127739.jpg
I want to be able to have it always on.
How can I short the button, without having to glue or tape it ...